Deck 9: Joining Data From Multiple Tables

Question 1

A table alias is assigned to a table in the WHERE clause.

Answer 1

False

Question 2

An outer join operator can be included in a FROM clause to list all rows from one table that do not have a corresponding row in the other table.

Answer 2

False

Question 3

The NATURAL JOIN keywords can be used to link two tables that have a commonly named and defined column.

Answer 3

True

Question 4

Equality, non-equality, and self-joins are all categorized as inner joins.

Question 5

Data stored in multiple tables can be combined through the use of an ORDER BY clause.

Question 6

Column qualifiers must be included in the WHERE clause if the columns used to join the tables have the same column names.

Question 7

A column qualifier is separated from the column name with a colon.

Question 8

An outer join operator consists of a minus sign enclosed in parentheses, (-).

Question 9

The most common type of join is an equijoin, which joins two or more tables together based upon the tables having equivalent data values in a common column.

Question 10

The NATURAL JOIN keywords can be used to create non-equality joins.

Question 11

A column qualifier is used to indicate the table containing the column being referenced.

Question 12

If a Cartesian join is used to link table A which contains two rows to table B which contains eight rows, there will be sixteen rows in the results.

Question 13

If a Cartesian join is used to link table A which contains five rows to table B which contains eight rows, there will be 13 rows in the results.

Question 14

An outer join only lists rows that contain a match in both tables.

Question 15

When a self-join is created, each copy of the table must be assigned a table alias.

Question 16

A table alias can be assigned in the FROM clause, even when tables are being joined using the NATURAL JOIN keywords.

Question 17

An inequality join refers to a join that is used to link a table to a copy of itself.

Question 18

The JOIN keyword is used in the WHERE clause to indicate the tables that should be joined or linked.

Question 19

A Cartesian join usually results from the user omitting the joining condition that links two or more tables together.

Question 20

The USING clause must be used with the JOIN keyword when linking tables that do not contain a commonly named column.

Question 21

A(n) $\underline { \text { outer } }$ join can be created by not including a joining condition in a SELECT statement. _________________________

Question 22

A(n) $\underline {\text { non-equality }}$ join is when a table is joined to itself. _________________________

Question 23

The $\underline {\text { outer join } }$ operator is used to combine the results of multiple SELECT statements. _________________________

Question 24

A cross join between two tables, containing four rows each, will display $\underline { \text { eight } }$ rows in its output. _________________________

Question 25

A Cartesian join can be created by not including a joining condition in the $\underline { \text { WHERE }}$ clause of a SELECT statement. _________________________

Question 26

The INTERSECT set operator only displays the rows returned by both queries.

Question 27

A(n) $\underline {\text { Cartesian Join }}$ replicates each row from the first table with every row from the second table. _________________________

Question 28

A full outer join can be created by including an outer join operator on both sides of the linking condition stated in the WHERE clause.

Question 29

The $\underline {\text { outer join } }$ operator is placed on the side of the joining condition that references the table containing the deficient rows. _________________________

Question 30

When using the JOIN...ON keywords to join four tables, both keywords must be repeated four times.

Question 31

The UNION set operator will not suppress rows that are returned by both queries.

Question 32

The JOIN keyword must be used in the $\underline { \text { WHERE } }$ clause of a SELECT statement. _________________________

Question 33

The outer join operator is placed on the side of the comparison that is deficient or is missing the matching rows.

Question 34

The MINUS set operator is used to display rows that were uniquely returned by the first query in the set.

Question 35

By default, use of the JOIN keyword creates an inner join.

Question 36

A(n) $\underline {\text { non-equality }}$ join is used when there are no equivalent rows of data in the tables that are being joined. _________________________

Question 37

A(n) $\underline { \text { non-equality } }$ join is also known as an equijoin, inner join, or simple join. _________________________

Question 38

Set operators are used to combine the results of multiple queries.

Question 39

The number of joining conditions required to join tables is always one less than the number of tables being joined.

Question 40

Tables can be joined in the $\underline {\text { FROM } }$ clause or the WHERE clause of a SELECT statement. _________________________

Question 41

If a table alias is assigned in the $\underline { \text { SELECT } }$ clause, it must be used any time the table is referenced in that SQL statement. _________________________

Question 42

A(n) $\underline { \text { inner join }}$ will only include rows that have matching rows in the other table. _________________________

Question 43

If you are joining $\underline {\text { five } }$ tables in a SELECT statement, five joining conditions will be required. _________________________

Question 44

By default, the $\underline { \text { JOIN } }$ keyword creates an inner join. _________________________

Question 45

The $\underline {\text { JOIN...USING } }$ keywords are used to join two tables that do not have a commonly named and defined column. _________________________

Question 46

Equality, non-equality, and self-joins are broadly categorized as $\underline {\text { outer }}$ joins. _________________________

Question 47

Which of the following is used to create an outer join in a WHERE clause?

A) FULL OUTER JOIN keywords
B) LEFT OUTER JOIN keywords
C) RIGHT OUTER JOIN keywords
D) outer join operator (+)

Question 48

Which of the following types of joins refers to joining a table to itself?

A) Cartesian join
B) equality join
C) self-join
D) outer join

Question 49

Which of the following types of joins is created by matching equivalent values in each table?

A) Cartesian join
B) equality join
C) non-equality join
D) outer join

Question 50

The $\underline { \text { ON } }$ clause can be used only if the tables being joined have a common column with the same name. _________________________

Question 51

A column qualifier indicates the $\underline { \text { column } }$ containing the data being referenced. _________________________

Question 52

Which of the following types of joins refers to results consisting of each row from the first table being replicated from every row in the second table?

A) outer join
B) non-equality join
C) self-join
D) Cartesian join

Question 53

When combining the results of two $\underline { \text { SELECT } }$ statements with the UNION keyword, duplicate rows are suppressed in the results. _________________________

Question 54

In a Cartesian join, linking a table that contains 10 rows to a table that contains 9 rows will result in ____ rows being displayed in the output.

A) 19
B) 18
C) 90
D) 89

Question 55

When combining the results of two SELECT statements with the $\underline {\text { MINUS } }$ keyword, duplicate rows are suppressed in the results. _________________________

Question 56

The JOIN keyword is included in which of the following clauses?

A) SELECT
B) FROM
C) WHERE
D) ORDER BY

Question 57

If you are joining two tables in a SELECT statement, $\underline { \text { three } }$ joining conditions will be required. _________________________

Question 58

If you are joining four tables in a SELECT statement, $\underline { \text { three } }$ joining conditions will be required. _________________________

Question 59

A table alias is assigned in the $\underline { \text { FROM } }$ clause. _________________________

Question 60

In Oracle11g, tables can be linked through which clause(s)?

A) SELECT
B) FROM
C) WHERE
D) both b and c

Question 61

Which of the following keywords is used to create an equality join?

A) NATURAL JOIN
B) JOIN...ON
C) JOIN...USING
D) all of the above

Question 62

The outer join operator in the WHERE clause cannot be used with which of the following operators?

A) IN
B) OR
C) AND
D) both a and b

Question 63

A join based upon a column from each table containing equivalent data is known as a(n) ____.

A) inequality join
B) outer join
C) equality join
D) all of the above

Question 64

Which of the following set operators will display the results of the combined SQL statements without suppressing duplicate rows?

A) UNION
B) UNION ALL
C) INTERSECT
D) MINUS

Question 65

Structure of the ORDERS table

Structure of the CUSTOMERS table
Which of the following queries will return the same results as the following SQL statement? SELECT

A) SELECT customer#, lastname, firstname, order#
FROM customers NATURAL JOIN orders;
B) SELECT customer#, lastname, firstname, order#
FROM customers JOIN orders USING (customer#);
C) SELECT c.customer#, lastname, firstname, order# FROM customers c, orders o;
D) both a and b

Question 66

Which of the following terms refers to a column with equivalent data that exists in two or more tables?

A) common column
B) equiv-column
C) inner columns
D) simple columns

Question 67

Structure of the ORDERS table

Structure of the CUSTOMERS table
Which SQL statement will return the same results as the following SQL statement? SELECT * FROM orders, customers;

A) SELECT * FROM orders CROSS JOIN customers;
B) SELECT * FROM orders, customers
WHERE orders.customer# = customers.customer#;
C) SELECT * FROM orders, customers
WHERE orders.customer# > customers.customer#;
C)customer#;
D) SELECT * FROM o orders , c customers
WHERE o.customer# =

Question 68

A table alias can consist of a maximum of ____ characters.

A) 12
B) 225
C) 255
D) 30

Question 69

Which of the following set operators will display only the unique results of the combined SQL statements?

A) UNION
B) UNION ALL
C) INTERSECT
D) MINUS

Question 70

Structure of the ORDERS table

Structure of the CUSTOMERS table
Which of the following queries will display data from both the ORDERS and CUSTOMERS tables?

A) SELECT * FROM orders, customers;
B) SELECT lastname, firstname, order#
FROM orders NATURAL JOIN customers;
C) SELECT lastname, firstname, order#
FROM orders, customers
WHERE orders.customer# = customers.customer#;
D) all of the above

Question 71

A column qualifier is separated from the column using which symbol?

A) comma (,)
B) plus sign (+)
C) period (.)
D) percent sign (%)

Question 72

Which of the following is an example of assigning "o" as a table alias for the ORDERS table in the FROM clause?

A) FROM o orders, c customers
B) FROM o.orders,
C) FROM orders o, customers c
C)customers
D) FROM orders.o, customers.c

Question 73

In which of the following examples is the ORDERS table used as a column qualifier?

A) o.order#
B) orders.order#
C) order#.o
D) order#.orders

Question 74

A table alias cannot be assigned in the FROM clause if which of the following keywords is used to join tables?

A) NATURAL JOIN
B) JOIN...ON
C) LEFT OUTER JOIN
D) FULL OUTER JOIN

Question 75

Which of the following keywords can be used to join two tables that do not contain a commonly named and defined column?

A) NATURAL JOIN
B) JOIN...ON
C) JOIN...USING
D) none of the above

Question 76

If you are attempting to join two tables that have multiple common columns, which of the following JOIN keywords should be used to specify how the tables should be linked?

A) OUTER JOIN
B) CROSS JOIN
C) JOIN...USING
D) none of the above

Question 77

Which of the following can only be used to link tables that have a common column?

A) FULL OUTER JOIN
B) JOIN...ON
C) NATURAL JOIN
D) CROSS JOIN

Question 78

Which of the following keywords is used to create a Cartesian join?

A) OUTER JOIN
B) CROSS JOIN
C) NATURAL JOIN
D) JOIN...USING

Question 79

Which of the following set operators can be used to make certain that only the rows returned by both queries are displayed in the results?

A) UNION
B) UNION ALL
C) INTERSECT
D) MINUS

Question 80

A(n) ____ is used to combine the results of two queries.

A) concatenation operator
B) set operator
C) comparison operator
D) logical operator